Box covering method and apparatus



Dec. 29, 1970 E. J. NEWTQN BOXCOVERING METHOD AND APPARATUS 4Sheets-Sheet 1 FIG.

Filed Feb. 27

FIG.

INVENTOR.

ERNEST J. NEWTON BY M'JWIJI ATTORNEYS Dec. 29, 1970 E. J. N'EWTONBOX'COVERING METHOD AND APPARATUS 4 Sheets-Sheet 2 Filed Feb. 2'7 1968FIG. 2

INVENTOR. ERNEST J. NEWTON BY W MQ- ATTORNEYS Dec. 29, 1970 Filed Feb.27 1968 4 Sheets-Sheet 3 A |o4- I04 FIG. 4

' INVENTOR. ERNEST J. NEWTON BY [W7 ATTORNEYS 1970 E. J. NEWTON BOXCOVERING METHOD AND APPARATUS 4 Sheets-Sheet 4 Filed Feb. 27, 1968 FIG.5

FIG. l2

INVENTOR. ERNEST J. NEWTON BY Mm- ,JIM 1440mm ATTORNEYS United StatesPatent 3,551,239 BOX COVERING METHOD AND APPARATUS Ernest J. Newton,3795 Wilson Ave., Montreal, Quebec, Canada Filed Feb. 27, 1968, Ser. No.708,705 Int. Cl. B29c 17/04 US. Cl. 156-213 14 Claims ABSTRACT OF THEDISCLOSURE This invention is a machine and method for covering boxshells with a deformable thermoplastic sheet material in which thematerial is first softened, then drawn down over a movable support forthe box shells so as to cover the outside surfaces thereof, and to formtents over the shells, suction is applied to the inside of the tents todraw the sheet material tightly against the outside surfaces of the boxshells and against a tucking member adapted to fit inside the shell, andthen the shell is between the box shells and the aforementioned tucking0 member to transfer and lay the material against the inside surfaces ofthe box shell.

BACKGROUND OF INVENTION It has been known in the art for some time thatit is possible to cover objects with a heat sensitive thermoplasticmaterial by first heating the materials so that they become stretchable,and then stretching them around the object to be covered. Many machinesand methods for doing this have been devised, but basically they fo lowthe same pattern in that either the object to be covered is stationaryand the material is brought around it and held in the envelopingposition until the material cools, or the sheet of plastic material isheld in a top position over the article to be covered, and then thearticle to be covered is moved into the sheet in order to draw the sheetaround the article. It is to be noticed that in these several methods,it is always the outside of the article that is being covered.

There also have been machines developed which are basically adapted tocovering the inside of an article with a plastic sheet, and again suchmachines first heat the plastic material and then by means of a form fitthe stretchable material inside the article whose insides are to becovered.

In the manufacture of jewelry boxes where box shells are to be covered.It has long been desired to use a plastic material, such as vinyl, inwhich the material may imitate other materials such as leather, cloth,etc. Using the machinery and methods of the prior art, it has beenpossible to cover either the outsides or the insides of these box shellsrelatively easy, but to date it has not been possible to cover both theoutside and the inside surfaces of the walls of the box shells in anautomatic single operation.

The reason for desiring to cover the inside surfaces of the shell wallsis that in a jewelry box, a pair of pads are used one of which coversthe bottom of the box and one of which covers the top of the box. Thepads are ornamental and serve not only to mount jewelry within the box,but also as a covering means to cover up the raw ice appearance of thematerial of the box shells themselves and any raw edges. In such a box,therefore, it is high- 1y desired to extend the covering material downon the inside surfaces of the walls of the box shell at least far enoughso that when the pad is inserted, it covers up the edges of the coveringmaterial, with the result that when one opens the box and looks at it,what one sees is the ornamental pad and completely covered walls. Todate, any covering of the inside walls with plastics have been a handoperation and therefore relatively ineflicient.

In summary, it is the purpose of this invention to provide a machinewhich when once loaded with a plurality of box shells, simultaneouslycovers that plurality of box shells both on the outside and then on theinner surfaces of the Walls of the box shells.

Therefore, among the several objects and advantages of the invention maybe noted the provision of apparatus for covering both the outside of thebox shell and the inside surfaces of the walls of the shell by at leasta semiautomatic operation, the covering taking place automatically oncethe apparatus has been loaded with the shells to be covered and thecovering material.

Another object of the invention is to provide apparatus of the abovekind in which means are provided for heating the covering material inorder to render it ductile prior to the covering operation, alloperations thereafter being automatic.

A further object of the invention is the provision of apparatus ofeither of the above kinds in which means are provided for drawing a tentaround the box shell to be covered, creating a diiferential pressurebetween the inside of the tent and the outside, and while maintainingsaid differential pressure, causing a relative motion between the shelland a tucking means so that material is tucked inside the box and laidagainst the inside surface of the box walls.

Yet another object of the invention is to provide apparatus of any ofthe above classes in which means are provided for guiding the box shellsduring the above operations, the guiding means being extended at thestart of the automatic operations, but being retractable duringsubsequent steps in order to allow the tucking operation to take place.

A still further object of the invention is to provide a method ofcovering a box shell which results in a fast operation of covering boththe outside and inside walls of the box shell on at least asemiautomatic basis.

A further object of the invention is the provision of any of theapparati set forth above or methods, which are simple to construct, easyto use, and economical in their operation.

The invention therefore accordingly comprises the elements andcombinations of elements, features of construction, arrangements ofparts, manipulation of the apparatus, the steps and sequence of stepsand features of operation, all of which will be exemplified in thestructures and methods hereinafter set forth, and the scope of theapplication of which will be indicated in the appended claims.

In the accompanying drawings, in which one of the various possibleembodiments of the invention is illustrated:

FIG. 1 is a plan view of one embodiment of the invention;

FIG. 2 is a front elevation of the embodiment of FIG. 1;

FIG. 3 is a sectional elevation of a portion of the FIG. 1 embodiment,taken in the directionof sight lines 33 on FIG. 1 and showing an initialposition of operating elements;

FIG. 4 is a sectional elevation similar to FIG. 3, but taken in thedirection of sight lines 44 on FIG. 1 and showing a second stage in theoperation of the apparatus;

FIG. is a view similar to FIG. 4, but showing the operating parts in athird stage of the operation;

FIG. 6 is a view similar to that of FIGS. 4 and 5, but enlargedthereover, to show a final position of the operating elements of theembodiment;

FIG. 7 is an illustration of a support element of the apparatus;

FIG. 8 is an illustration of an alternate support element of theapparatus;

FIG. 9 is an illustration of a tucking element used in the invention;

FIG. 10 is an illustration of a combined support and guide member usedin the apparatus for certain box-shells;

FIG. 11 is a sectional elevation of the support element of FIG. 10 incombination with a tucking element; I

FIG. 12 is an illustration of a portion of a U-shaped, ornamentalfastening-frame used to assist in holding a covering on a box; and

FIG. 13 is an illustration of a box shell showing the use of the FIG.12. fastening frame.

Throughout the drawings, dimensions of certain of the parts as shown mayhave been modified and/or exaggerated for the purposes of clarity ofillustration and understanding of the invention. Throughout thedrawings, similar reference characters indicate corresponding parts.

Referring first to FIGS. 1, 2 and 3, there are shown a plan view, afront elevation, and a sectional elevation of one of several possibleembodiments of the invention. In this embodiment, there is shown aheating structure indicated generally by numeral 2, the structure beinga sliding framework or box containing an ohmic heating element indicatedby the dotted lines 4. The heating element 4 is connected inconventional manner to a source of electrical power (not shown). Heater2 is an open-faced box structure 6, for example, with the structurefacing downwardly so that element 4 may radiate its heat directlydownwardly. Heater 2 is supported by means of round side rails 8, thelatter sliding in the half round tubes 10 which are mounted,conventionally, one on each side of the machine or supports 7. Anupright handle 12 is fastened to the heater 2 so that the heaterstructure as a whole may be pulled forwardly on the machine into aposition in which the radiated heat from heating element 4 will heat asheet of plastic which is to be used to cover box-shells.

Attached to the front end of the box 6 is a curved strap 14 whichserves, when the heater 2 is pulled forward, to actuate a switch 16- inconventional manner. Switch 16 starts a timing element which may be setto a given number of seconds or minutes. At the end of the set period oftime, the timer provides an indication that the period is ended, andthen the heating element 4 is shut off and the box 6 is moved back tothe position of FIG. 1.

Attached to the front of the apparatus is the covering mechanism proper,indicated generally by numeral 18. It comprises a plate bed 20 havingdependent therefrom the side walls 22 and a bottom plate 24, the sidesand bottom plate 24, the sides and bottom plate forming a chamber 23beneath the bed plate 20. Plate 20 and its dependent chamber 23 aresuitably supported on a platform 90 which in turn is supported by thelegs 28 in conventional manner. A heat shield is fastened to the back ofplatform 90 and serves to protect the plate 20 from any stray radiationfrom heater 2.

Mounted against the underside of the bottom 24 is one end 30 of an aircylinder 32 which is of the double acting kind. That is, introduction ofair at one side of the piston of the cylinder will move the piston out,and introduction of air at the other side of the piston (withsimultaneous exhaust of air on the first side) will move the piston inthe other direction. The cylinder 32 has a bottom plate 34 attached toits other end, and to this plate 34 is attached the mounting plate 36 ofa second air cylinder 38. Cylinder 38 is, like cylinder 32, of thedouble-acting kind.

The piston rod 40 of cylinder 32 extends upwardly through a suitablyprovided aperture in the plate 24, and the upper end of the pistonsupports and actuates a platform 42 so that operation of the cylinder 32will move the plate 42 upwardly and downwardly.

Slidably mounted in the bed plate 20 through suitable apertures 44therein are the supporting shafts or plungers 46. Plungers 46 are movedupwardly and downwardly by motion of plate 42 to accomplish certainuseful operations of the apparatus, as will be described below.

Referring to any of FIGS. 3-8, and particularly FIG. 7, a plunger 46 isshown in greater detail. Provided in the side of the plunger itself is akeyway 48. Mounted at the top of the plunger 46 is a guide plate '50,each guide plate comprising a body portion 52 and a plurality of fingers56 which are swiveled in conventional manner on the body as shown. Theguide plate is held onto the top of the plunger 46 by means of a screw58.

The function of the guide plates 50 is to guide and align a box shell(which is to be covered) on top of the plungers 46, so that when theplunger and its guide plate are lowered, the box shell will fit downover a skirt or tucking element 60 on the base 20, now to be described.

Mounted on the bed plate 20 are a number of the above mentioned tuckingelements 60, each element comprising a base portion 62 and theupstanding skirt portion 64. The skirt portion 64 is made smaller insize than the inside dimensions of a box shell to be covered, but hasthe same cross-sectional shape as the box shell. The size difference ispreferably sufiicient to accommodate slightly more than two thicknessesof the material being used to cover the box shell. As shown in FIG. 6,when the platform 42 has been moved down so that the plungers 46 arefully downward, the guide plates 50 are completely enclosed within theskirt portion 64, the fingers folding upwardly and inwardly in order toaccommodate this downward motion of the guide plates. On the other hand,while the guide plates are in their extended position, it will benoticed (see FIGS. 4 and 5) that the fingers 56 extend outwardlysulficiently to contact the side walls of the box shell 66 and thusguide the box shell centrally on the plunger 46 and in position to bemoved downwardly over the upstanding skirts 64.

Where the construction of the box permits it, instead of using the guideplates 50, a box support and guide element 70 may be used, this boxsupport element being slightly smaller than the inside dimensions of thebox shell and small enough to fit down into element 60. Preferably, ifthe box shell is rounded, the top of the box guide 70 is rounded insimilar manner. In general practice, particularly in regard to jewelryboxes, it is the practice for the box shell used as the base to have aflat, bottom. For such a flat bottom box shell, it will be found thatthe guide plates 50 are the ones to be used for guiding of the shell onthe plungers 46. On the other hand, in jewelry boxes, it is quiteconventional to use a domed top box shell, and in such instances, thebox support 70 will be sufiicient to centralize such a dome shell on therespective plunger 46 so as to be aligned with the skirt members 60.

There will be instances, however, where the box shell to be covered isof such depth that both the guide plate and the support 70 will need tobe used. In this instance, the support 70* governs the vertical positionof the box shell during the covering operation, and the guide plate 50determines the lateral position of the box shell so that the latter willbe centered over the skirt 60. A reference to FIGS. 10 and 11 illustratethe use of the combination of the top support 70 and a finger plate 50with a skirt member 60, FIG. 11 showing the plunger 46, guide plate 50and top support 70 being withdrawn completely in the skirt 60. Asillustrated the shell 66 rests down on top of the skirt 64, and thetucking and lay-up features of the covering material 122 are clearlyshown.

Referring again to the tucking element 60, a pin 76 extends laterallyinto therein to intersect with the aperture 78 through which slides theplunger 46. The pin 76 engages the keyway 48 in order to prevent theplunger from turning within the tucking element. In order to permit airto be drawn from the top of the plate downwardly through the plate andinto the chamber 23, a suitable groove 80 is provided in the peripheryof the aperture 78.

A plurality of elements 60 is provided and each is held to the base 20by means of conventional machine screws 65.

It is also to be noted (see FIG. 6) that in order to make chamber 23relatively airtight around its peripheral joints, the plate 20 ismounted on the side walls 22 by means of screws 82 and by the use of arubber gasket 84. The rubber gasket 84 is not necessary if asufliciently large vacuum pump is used, but is preferred. In similarmanner, the plate 24 is mounted to the underneath side of the walls 22by means of the conventional screws 86, and again, a rubber gasket 88may be used to effectuate a rela-- tively tight seal of the plate 24 tothe walls. Also, if

necessary though not shown, the piston rod 40 may extend through asuitable packing gland in the plate 24.

The piston 100 of the cylinder 38 is attached to a thrust plate 102 onwhich are mounted the four sulpport shafts 104. These shafts extendupwardly and pass through suitable apertures in the platform 90 so as toclear the bed plate 20.

Mounted at the top of the shafts 90 is a framework indicated generallyby numeral 106 which may be made of any suitable material and comprisestwo aligned frames 108 and 110. The opening within the two frames, whichare in alignment, is just sufficient to clear the bed plate 20 when theframes are lowered down to platform 90 by the shafts 104, as will bedescribed below. The upper frame 110 is suitably hinged to the frame 108along one edge so that the upper frame may be swung upwardly. The topsurface of the lower frame 108 is covered with a rubberlike material112, and the lower face of the upper face 110 is in like manner coveredwith a rubberlike material 114.

Stretched across the bottom plane of the upper frame 108 are a pair ofwires 116, these wires being held tightly to the frame and in stretchedcondition by any suitable means. In the present embodiment, since onlyfour of the tucking elements 60 are shown, only a pair of wires isneeded, these wires intersecting about the middle of the open face ofthe frame to form four spaces defined by the wires and inside edges ofthe frames. Of course, if more than four individual covering units aredescribed, then sufficient additional wires are used so that eachcovering unit is associated with such an opening formed by the wires orthe wires and the edges of the frames 108 and 110.

The thrust of the piston 100 is sufiicient so that when the piston isextended, the frames 108 and 110 are drawn down past the bed plate 20and come to rest against the apron or platform 90. In order to providean airtight seal, a rubber gasket 120 is fastened to the bottom surfaceof the frame 108, and contact of the gasket 120 with the top of plate 90will provide a sutficiently airtight seal. It will be noticed that whenthe frames 108-110 are thus drawn downward, the wires 116 are drawntightly down against the top of the bed plate 20.

The use and operation of the device thus described is as follows: Withthe heating element 2 in its retracted position as shown in FIG. 1, andplatform 42 raised to its up position by actuations of piston 40, boxshells are placed on the supports 50 (see FIG. 3). Upper frame 110 isthen raised upwardly from frame 108, the frame carrying with it thewires 116. A sheet of covering material 122 is then laid across thelower frame 108, and then the upper frame 110 is brought back to restagainst the sheet, thus clamping the sheet between the rubber gaskets112 and 114. It will be observed, that in this position, the wires 116overly the sheet. Suitable locking means, such as the pivoted lever orlatch bar 123 is used to lock frame 110 to frame 108 in conventionalmanner.

Next, the heating device 2 is pulled forwardly by means of the handle 12to come above the frames 108 and 110, thus overlying the plasticmaterial, FIG. 3 showing the parts in this position. At the same time,the heating element 4 is connected to a source of electrical power bymeans of a conventional switch. Upon pulling the heating element 2forwardly, the switch 16 is actuated which starts the aforesaid timeroperating. After a given interval of time (for example, seven seconds)it will be found that the radiated heat from the heating element 4 hasbeen sufiicient to heat the plastic to its stretching and forming point.For example, where a vinyl material is used, it will be found that whenthe material is raised to approximately a temperature of 200 thematerial will have sufficient ductility for the remaining coveringoperations. Because of the timer, this point will be indicated when thebell of the timer or other indicating means is activated. At that point,power is shut off the heating element 4, and the whole heater mechanism2 is pushed back to its position shown in FIG. 1.

With the plastic covering material still in a flexible condition, thecylinder 38 is actuated, for example, by means of the double actingvalve 130, to move the piston downwardly, and thus move the shafts 104so as to pull the frames 108-110 downwardly until they come to rest inthe position shown in FIG. 4.

In view of the fact that the shells 66 are in the upward position, whenthe framework 108-110 is moved downwardly by means of shafts 104, thevinyl plastic 122 is also drawn downwardly by means of the Wires 116 andthe frame so as to form tents 124 (see FIG. 4) over each of the boxshells 66 and the element 60 below it. It will also be noted that thewires 116 are pulled tightly enough against the top of the bed plate 20,and the frame 108 is held tightly enough against the apron 90, so thatvirtually an airtight seal is created within the several tents (four, inthe embodiment shown in FIG. 1). With the frames 108110 held in thisposition, a valve 134 is actuated, one side of the valve being connectedby tubing 136 to a suitable vacuum pump (not shown) and the other sideof the valve being connected by tube 138 to a suitable aperture 139 inthe bottom 24. As a result, the chamber 23 is evacuated, and this sucksair from within the tents 124 as thus formed, with the result (see FIG.5) that the covering material 122 forming the tents 124 is drawninwardly to lie against the walls of the skirts 64, and it will beobserved that at the points indicated by numeral 140 the plasticcovering material has been drawn inwardly to overly the top perimetersof the skirts.

While maintaining the frames 108-110 and the plastic material 122 in thedownward position shown in FIGS. 5 and 6, and while maintaining thevacuum, a doubleacting valve 132 which controls cylinder 32 is nowactuated to one of its positions, with the result that air cylinder 32retracts its piston 40. This retracts the platform 42, and theindividual plungers 46 descend. This operation lowers the shells downover the skirt 64, and it will be observed that as the shells are solowered, the skirts act a tucking agents to lay-up the material whichformerly was against their sides over against the inside surfaces of thewalls of the box shells. See FIG. 6.

In order to retain the material in place, one may coat the insidesurface of the shells with a suitable heat activated adhesive, prior toloading the box shells into the machine. The plastic 122 will stillretain enough of its heat to activate the adhesive, thus causing thecovering material to stick to the inside surfaces of the box shellwalls. Or, an adhesive may be used which is self-curing without heat.

The material will shortly have cooled down to the point that the frames108-110 may be lifted upwardly by suitable actuation of the valve 130,the vacuum having been broken by opening the valve 134. The frame 110 isnow pivoted upwardly, and the shells together with their coveringmaterial may be withdrawn from the machine.

At this point, further shells are put on the supports, another sheet ofplastic material is laid across the frame 108, and the operations givenabove are repeated. While this set is being covered, the covered shellsof the first set are severed from the rest of the sheet material by anyconvenient method, either mechanical or by hand.

Due to an adherent memory of a plastic material such as vinyl, there maybe a tendency for the covering material to draw backwards, and thuspossibly pull the covering material away from the inside of the boxshell sides. In order to eliminate this, as mentioned above a suitableadhesive may be used which will cover not only the outside of the boxshell but the insides of the box shell walls. When this adhesive is set,it will be sufficiently strong to prevent any such retraction. On theother hand, the withdrawal may be prevented by clamping the plasticcovering material about the edge of the box. This is conveniently doneby using, for example, a typical ornamental U-shaped framework 140illustrated in FIG. 12. FIG. 13 show a box having been covered and theframework in place, the framework being clamped against the coveringmaterial in conventional fashion in order to more firmly secure thecovering material to the box wall. If desired, both adhesive and theclamping frame 140 may be used.

Throughout the description, little mention has been made of thematerials from which the various components are to be made. This iswithin the engineering skill of the art, and steel and brass may be usedwhere a designers choice indicates that they should be used. Theelements 60 may be formed out of metal, which is preferred; or ifdesired for economy, they may be molded from a suitable plastic materialsuch as an epoxy resin.

Other means may be used to guide the box shells so that they will fitnicely down over the several elements 60. Whatever the means used, it isimportant to notice that in the method of covering described herein, thebox shells are held away from the tucking mechanisms 60 while a tent ofthe plastic covering material is formed over the box shell. Air is thenwithdrawn from within the tent in order to cause the covering materialto fold inwardly. At that point, a relative motion between the box shelland the tucking element is caused to occur, whereby the tucking elementtelescopes up within the shell. By doing this, material which hashitherto been caused to lay-up against the outside of the tuckingelement, due to the vacuum, is caused to be transferred to the insidewalls of the box shells, whereat the material is secured in place eitherby a simple adhesive or by a member which is clamped around the edge ofthe box shell.

In view of the above it will be seen that the several objects of theinvention are achieved and other advantageous results attained.

It is to be understood that the invention is not limited in itsapplication to the details of construction, and arrangement of partsillustrated in the accompanying drawings, since the invention is capableof other embodiments and of being practiced or carried out in variousways. Also, it is to be understood that the phraseology or terminologyemployed herein is for the purpose of description and not of limitation.

As many changes could be made in the above construc tions withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings, shall be interpreted as illustrative and not in a limitingsense, and it is also intended that the appended claims shall cover allsuch equivalent variations as come within the true spirit and scope ofthe invention.

Having described the invention, what is claimed is:

1. The method of covering with a covering material an open-faced hollowarticle having a bottom and a plurality of side walls extendingtherefrom, comprising the steps of supporting the article by its bottomon a support on a base with the open face of the article facing on one 8direction, and the support being movable relative to the base;

supporting a sheet of covering material adjacent the outerface of thebottom of the article;

supporting on the base a tucking element projecting therefrom towardsaid open face, said element having the same cross-sectional shape asthat of the article but being smaller and thereby being adapted to moveinto the hollow article;

stretching the sheet of covering material over the article and towardthe base to form a tent of said material over the article;

causing a differential pressure to exist between the air pressures onthe outside and inside of said tent with the air presssure inside thetent being less than that outside, whereby the sheet is pressed snuglyagainst the outer surface of the article and against the outer surfacesof said tucking element;

While maintaining said differential pressure, moving the article andtucking element toward each other until said element at least partiallyenters the open face of the article, whereby said material is pulledfrom the outer walls of said element and laid against the insidesurfaces of said sides to cover at least a portion thereof; and

thereafter causing said material to be held tightly at least to the edgeportions of the sides of the article.

2. The method of claim 1 in which said sheet of covering material issupported at its border in a frame movable toward said base.

3. The method of claim 1 in which said sheet of covering material issupported at its periphery by a frame, and including a grid of elongatedmembers overlying the plastic sheet and forming a plurality of openingslarge enough to pass over said article, said members drawing said sheetover the article by passing over the article and against said base,thereby to form said tent.

4. The method of claim 1 in which the differential air pressure iscaused by sucking air from within said tent.

5. The method of claim 1 in which the step of causing the said materialto be held tightly against the sides of the article includes the step ofapplying, over said material covering the edges of the sides, aframework of stiff material having a U-shaped cross-section, theframework clamping the material against said edge portions.

6. The method of claim .1 in which the inside surfaces of said sides arecovered with an adhesive, said adhesive tightly binding the coveringmaterial to the inside surfaces as the material is laid thereon duringrelative motion between said element and the article.

7. The method of claim 1 in which said covering material is athermoplastic resin.

8. The method of claim 7 including the step of heating the materialprior to forming said tent, to make said material more ductile.

9. The method of claim 8 in which the plastic resin is vinyl.

10. Apparatus for covering an open-faced hollow article with a layer ofcovering material, the article having a bottom and a plurality of sidesupstanding therefrom comprising:

a base;

a support for the article mounted on the base and adapted to move towardand away from the base;

a tucking element upstanding from the base and extending toward thesupport, said element having the same cross-sectional shape as thearticle but being small enough to fit into the open face of the latter,whereby upon motion of the support toward the base the article isadapted to fit over said element;

means for forming a tent of said material over the article with thelatter on the support, said base constituting the bottom of the tent andthe article being at the top of the tent;

means for causing the air pressure outside the tent to be greater thanthat inside the tent, thereby to force said material against the outersurfaces of the article and said element; and

means for moving said support and article toward said elementsufiiciently far so that at least a portion of said element enters thearticle while maintaining the outside air pressure greater than theinside air pressure, whereby said material removed from the sides ofsaid element and is laid against at least portions of the insidesurfaces of said sides.

11. The apparatus of claim 10 in which said support is mounted on thebase by means of a plunger slidable through the "base, the apparatusincluding movable means workable against the free end of the plunger tomove said support.

12. The apparatus of claim 11 including guide means mounted on theplunger and movable therewith, the guide means constituting a flat plateso shaped as to fit within said element when the support moves towardthe latter; said plate having fingers pivoted thereto at its periphery,the fingers being adapted to fold upon entry of the plate into saidelement; and the envelope defined by the free ends of the fingers beingthe shape and size of the crosssection of the interior of the article,whereby, when the article is On the support prior to its motion towardsaid element, said fingers are extended and center the article withrespect to said element.

13. The apparatus of claim 10 in which the means for forming said tentcomprises:

a frame adapted to hold a sheet of the material initially over anarticle on the support;

a grid of elongated members overlying said material and forming openingslarge enough to pass over said article, the grid being movable towardthe base far enough to draw the material over said articles when on thesupport, and down against the base.

14. The apparatus of claim 10 including means for heating said materialto render it stretchable prior to forming said tent.

References Cited UNITED STATES PATENTS 2,621,142 12/1952 Wetherell156-216X 3,146,143 8/1964 Bolesky et al. 156216X 3,147,172 9/1964 Wesaet a1 156-216X 3,325,329 6/ 1967 Bolesky 156216X 3,329,545 7/1967Hamilton 156213 SAMUEL W. ENGLE, Primary Examiner US. Cl. X.R.

3 3 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,551,239 Dated December 29, 1970 Inventor(s) Ernest J. Newton ppears inthe above-identified patent It is certified that error a herebycorrected as shown below:

and that'said Letters Patent are Column 3 lines 57 and 58, cancel thephrase "the sides and bottom plate 24,".

Column 5, line 47 "described" should read "desired".

Signed and sealed this 23rd day of March 1971 (SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR.

Commissioner of Patents Attesting Officer

